A microparticle measuring apparatus (for example, a flow cytometer) which optically measures characteristics of a microparticle such as a cell is known.
In the flow cytometer, sample liquid including the cell flows through a flow passage formed in a flow cell or a microchip, and a detector detects fluorescence or scattering light generated from the cell by irradiating the cell which through-flows inside the flow passage with laser, so that an optical characteristic of the cell is measured. In addition, in the flow cytometer, as a measurement result of the optical characteristic, a population (a group) which is determined to satisfy a predetermined condition is separately collected from the cell.
For example, in PTL 1, as a microchip-type flow cytometer, “a microparticle splitting device including a microchip provided with a flow passage through which liquid including a microparticle flows, and an orifice which ejects the liquid flowing through the flow passage into a space outside the chip, an oscillating element for discharging the liquid to be liquid droplets in the orifice, a charging unit for applying an electric charge to the discharged liquid droplets, an optical detection unit which detects optical characteristic of the microparticle flowing through the flow passage, counter electrodes which are disposed to face each other and to interpose the liquid droplets moved along a movement direction of the liquid droplets which are discharged into the space outside the chip, and two or more containers which collect the liquid droplets passed between the counter electrodes” is disclosed.